4 files changed, 146 insertions, 4 deletions

diff --git a/Android.mk b/Android.mk
index 98c442791..fbddef7e3 100644
--- a/Android.mk
+++ b/Android.mk
@@ -22,6 +22,7 @@ LOCAL_SRC_FILES := \
     twrpTar.cpp \
 	twrpDU.cpp \
     twrpDigest.cpp \
+    find_file.cpp
 
 LOCAL_SRC_FILES += \
     data.cpp \
diff --git a/data.cpp b/data.cpp
index c9628a411..1fbe0ffad 100644
--- a/data.cpp
+++ b/data.cpp
@@ -45,6 +45,7 @@
 #ifndef TW_NO_SCREEN_TIMEOUT
 #include "gui/blanktimer.hpp"
 #endif
+#include "find_file.hpp"
 
 #ifdef TW_USE_MODEL_HARDWARE_ID_FOR_DEVICE_ID
 	#include "cutils/properties.h"
@@ -940,17 +941,31 @@ void DataManager::SetDefaultValues()
 #ifndef TW_MAX_BRIGHTNESS
 #define TW_MAX_BRIGHTNESS 255
 #endif
+	string findbright;
 	if (strcmp(EXPAND(TW_BRIGHTNESS_PATH), "/nobrightness") != 0) {
-		LOGINFO("TW_BRIGHTNESS_PATH := %s\n", EXPAND(TW_BRIGHTNESS_PATH));
+		findbright = EXPAND(TW_BRIGHTNESS_PATH);
+		LOGINFO("TW_BRIGHTNESS_PATH := %s\n", findbright.c_str());
+		if (!TWFunc::Path_Exists(findbright)) {
+			LOGINFO("Specified brightness file '%s' not found.\n", findbright.c_str());
+			findbright = "";
+		}
+	}
+	if (findbright.empty()) {
+		// Attempt to locate the brightness file
+		findbright = Find_File::Find("brightness", "/sys/class/backlight");
+	}
+	if (findbright.empty()) {
+		LOGINFO("Unable to locate brightness file\n");
+		mConstValues.insert(make_pair("tw_has_brightnesss_file", "0"));
+	} else {
+		LOGINFO("Found brightness file at '%s'\n", findbright.c_str());
 		mConstValues.insert(make_pair("tw_has_brightnesss_file", "1"));
-		mConstValues.insert(make_pair("tw_brightness_file", EXPAND(TW_BRIGHTNESS_PATH)));
+		mConstValues.insert(make_pair("tw_brightness_file", findbright));
 		ostringstream maxVal;
 		maxVal << TW_MAX_BRIGHTNESS;
 		mConstValues.insert(make_pair("tw_brightness_max", maxVal.str()));
 		mValues.insert(make_pair("tw_brightness", make_pair(maxVal.str(), 1)));
 		mValues.insert(make_pair("tw_brightness_pct", make_pair("100", 1)));
-	} else {
-		mConstValues.insert(make_pair("tw_has_brightnesss_file", "0"));
 	}
 #endif
 	mValues.insert(make_pair(TW_MILITARY_TIME, make_pair("0", 1)));
diff --git a/find_file.cpp b/find_file.cpp
new file mode 100644
index 000000000..f56f243de
--- /dev/null
+++ b/find_file.cpp
@@ -0,0 +1,89 @@
+/*
+		Copyright 2014 TeamWin
+		This file is part of TWRP/TeamWin Recovery Project.
+
+		TWRP is free software: you can redistribute it and/or modify
+		it under the terms of the GNU General Public License as published by
+		the Free Software Foundation, either version 3 of the License, or
+		(at your option) any later version.
+
+		TWRP is distributed in the hope that it will be useful,
+		but WITHOUT ANY WARRANTY; without even the implied warranty of
+		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+		GNU General Public License for more details.
+
+		You should have received a copy of the GNU General Public License
+		along with TWRP.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <string>
+#include <vector>
+#include <dirent.h>
+#include "find_file.hpp"
+#include "twrp-functions.hpp"
+#include "twcommon.h"
+
+using namespace std;
+
+string Find_File::Find(const string& file_name, const string& start_path) {
+	return Find_File().Find_Internal(file_name, start_path);
+}
+
+Find_File::Find_File() {
+}
+
+string Find_File::Find_Internal(const string& filename, const string& starting_path) {
+	DIR *d = opendir(starting_path.c_str());
+	string new_path, return_path;
+	vector<string> dirs;
+	vector<string> symlinks;
+	unsigned index;
+
+	// Check to see if we have already searched this directory to prevent infinite loops
+	if (std::find(searched_dirs.begin(), searched_dirs.end(), starting_path) != searched_dirs.end()) {
+		return "";
+	}
+	searched_dirs.push_back(starting_path);
+
+	if (d == NULL) {
+		LOGERR("Find_File: Error opening '%s'\n", starting_path.c_str());
+		return "";
+	}
+
+	struct dirent *p;
+	while ((p = readdir(d))) {
+		if (!strcmp(p->d_name, ".") || !strcmp(p->d_name, ".."))
+			continue;
+		new_path = starting_path + "/";
+		new_path.append(p->d_name);
+		if (p->d_type == DT_DIR) {
+			// Add dir to search list for later
+			dirs.push_back(new_path);
+		} else if (p->d_type == DT_LNK) {
+			// Add symlink to search list for later
+			symlinks.push_back(new_path);
+		} else if (p->d_type == DT_REG && filename == p->d_name) {
+			// We found a match!
+			closedir(d);
+			return new_path;
+		}
+	}
+	closedir(d);
+
+	// Scan real directories first if no match found in this path
+	for (index = 0; index < dirs.size(); index++) {
+		return_path = Find_Internal(filename, dirs.at(index));
+		if (!return_path.empty()) return return_path;
+	}
+	// Scan symlinks after scanning real directories
+	for (index = 0; index < symlinks.size(); index++) {
+		char buf[PATH_MAX];
+		// Resolve symlink to a real path
+		char* ret = realpath(symlinks.at(index).c_str(), buf);
+		if (ret) {
+			return_path = Find_Internal(filename, buf);
+			if (!return_path.empty()) return return_path;
+		}
+	}
+	return "";
+}
diff --git a/find_file.hpp b/find_file.hpp
new file mode 100644
index 000000000..8833e9ad2
--- /dev/null
+++ b/find_file.hpp
@@ -0,0 +1,37 @@
+/*
+        Copyright 2014 TeamWin
+        This file is part of TWRP/TeamWin Recovery Project.
+
+        TWRP is free software: you can redistribute it and/or modify
+        it under the terms of the GNU General Public License as published by
+        the Free Software Foundation, either version 3 of the License, or
+        (at your option) any later version.
+
+        TWRP is distributed in the hope that it will be useful,
+        but WITHOUT ANY WARRANTY; without even the implied warranty of
+        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+        GNU General Public License for more details.
+
+        You should have received a copy of the GNU General Public License
+        along with TWRP.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef Find_File_HPP
+#define Find_File_HPP
+
+#include <string>
+#include <vector>
+
+using namespace std;
+
+class Find_File {
+
+public:
+	static string Find(const string& file_name, const string& start_path);
+private:
+	Find_File();
+	string Find_Internal(const string& filename, const string& starting_path);
+	vector<string> searched_dirs;
+};
+
+#endif